Frontiers in Oncology (Nov 2022)

Proton therapy for isolated local regional recurrence of breast cancer after mastectomy alone

  • Brady S. Laughlin,
  • Ronik S. Bhangoo,
  • Joshua R. Niska,
  • Cameron S. Thorpe,
  • Marlene E. Girardo,
  • Justin D. Anderson,
  • Heidi E. Kosiorek,
  • Lisa A. McGee,
  • William F. Hartsell,
  • John H. Chang,
  • Carl J. Rossi,
  • Henry K. Tsai,
  • Isabelle J. Choi,
  • Carlos E. Vargas

DOI
https://doi.org/10.3389/fonc.2022.925078
Journal volume & issue
Vol. 12

Abstract

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Purpose/ObjectivesTo assess adverse events (AEs) and disease-specific outcomes after proton therapy for isolated local-regional recurrence (LRR) of breast cancer after mastectomy without prior radiotherapy (RT).Materials/MethodsPatients were identified from a multi-institutional prospective registry and included if diagnosed with invasive breast cancer, initially underwent mastectomy without adjuvant RT, experienced an LRR, and subsequently underwent salvage treatment, including proton therapy. Follow-up and cancer outcomes were measured from the date of RT completion.ResultsNineteen patients were included. Seventeen patients were treated with proton therapy to the chest wall and comprehensive regional lymphatics (17/19, 90%). Maximum grade AE was grade 2 in 13 (69%) patients and grade 3 in 4 (21%) patients. All patients with grade 3 AE received > 60 GyE (p=0.04, Spearman correlation coefficient=0.5). At the last follow-up, 90% of patients were alive with no LRR or distant recurrence.ConclusionsFor breast cancer patients with isolated LRR after initial mastectomy without adjuvant RT, proton therapy is well-tolerated in the salvage setting with excellent loco-regional control. All grade 3 AEs occurred in patients receiving > 60 GyE.

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